1. Field of the Invention
The present invention generally relates to a method and an electronic apparatus for verification, in particular, to a method and an electronic apparatus for angle estimation verification.
2. Description of Related Art
Following the rapid increase in population and gradual recovery on the global economy, disposable personal income and consumption ability have been increased year by year and lead to continuously increasing global vehicle sales. With the continuous growth in vehicle sales, the automobile electronic industry has been dramatically developed which covers six major aspects including an automobile safety system, an automobile body system, a driver information system, a suspension & chassis system, an engine transmission system, and a security system, where the automobile safety system hold the highest compound annual growth rate among these aspects.
With an ever-increasing number of vehicles, the probability of road traffic accidents has consequently gone up. A European study shows that 0.5 seconds of early warning time may prevent at least 60% of rear-end collisions, 30% of head-on collisions, and 50% of road-related accidents; 1 second of early warning time may prevent 90% of accidents. Therefore, the vehicle safety system is crucially important.
In terms of functionality and category, the vehicle safety system may be classified into an active type and a passive type. Prior to year 2000, the active safety system such as seat belts or safety airbags dominates the market. With the advancement of semiconductor technology and high frequency electronic circuit technology since year 2000, electronic systems with a high computation performance have been able to be manufactured. Moreover, due to people's high demand on the safety, the safety system has been transited from passive reduction in accidents to active avoidance from accidents. Thus, the active safety system has been rapidly developed. In an actual driving situation, the active safety system may provide an early warning prior to any accident occurring by reminding the driver or actively controlling the vehicle to avoid from a dangerous situation to protect the driver, and thus the active safety system may be more important than the passive safety system.
Accordingly, the current active safety system has undergone a significant progress, which dominates the overall automobile safety system market. The current active safety system includes an adaptive cruise control (ACC) system, a Stop & Go system, a lane departure warning system, an environment recognition system, a collision avoidance system, and an advanced driver aid system (ADAS). The major development on the active safety system lies in the following three categories: basic collision-avoidance warning technology, advanced collision-avoidance technology, and basic driver information equipment. The basic collision-avoidance warning technology involves adaptive cruise control, rear end collision-avoidance, frontal pedestrian and obstacle detection. The advanced collision-avoidance technology involves avoidance from improper lane change and collision-accidents at crossroads. The basic driver information equipment includes road guide, real-time traffic, driver information and navigation.
The European governments are focusing on developing a driver monitoring system, a road condition detection system, and a smart steering control. The U.S. government is cooperating with General Motors to develop and test a rear view collision avoidance system. Japan is conducting a large amount of on-road verification test on Smartway which employs various sub-systems such as a front radar and a lane departure warning indicator to perform various advanced functions such as cruise control, collision avoidance, and lane tracking.
The adaptive cruise control in the active system has been extended toward a constant-speed cruise control, the application of which includes a high-speed, low-speed, and all-speed cruise controls. The principle of the adapted cruise control is that, during a constant-speed driving, a radar system installed in the front of the vehicle is utilized for detecting the traffic situation in the front of the vehicle to maintain a safe driving distance. When another vehicle enters the lane and results in an insufficient safe driving distance, the driving speed of the vehicle may be automatically reduced. When there is a sufficient safe driving distance, the driving speed of the vehicle may be automatically increased to the speed set by the driver. Such adaptive cruse control system is provided in most of the high-end vehicles. On the other hand, the Stop & Go system is an advanced version of the adaptive cruise control system, where the improvement of which is that it may optionally reduce the speed to stop the vehicle rather than shut down the system function at a specific speed. Additionally, the Stop & Go system may automatically accelerate the vehicle to a preset speed and maintain the vehicle distance once the vehicle ahead moves again, where the preset speed may be automatically adjusted based on the traffic. Hence, the Stop & Go system is suitable for handling traffic congestion in urban areas.
In view of the foregoing, in the adaptive cruise control and Stop & Go systems, the front collision-avoidance radar is a crucial component. Once the radar misjudges and provides false information, it will cause the entire system to respond incorrectly. Target detection is an important aspect in a vehicle radar system, which not only provides a relative position of the target so as to enhance the driving safety but also estimates a lane change and an actual traffic condition through the motion trajectory of the target in the front.
However, when the radar system is in an environment where multiple targets exist, referred to as an overlapping event, the targets may correspond to exact or close values in the frequency spectrum. If no suitable determination mechanism is provided in the radar system, it may result in an incorrect estimation on the target.